Antenna



Nov. 11, 1930. BETHENQD 1,781,046

ANTENNA Filed July 1 1925 Fig. i

INVENTOR SEPH B T 0D TORNEY Patented Nov. 11, 1930 UNITED TE iPATENT" ciil:

v aosErH YIBETHQENOD, oFfrA eI's, rRAivoE ANTENNA Applicationfiled July1, 1925, Serial no; 40,74, and in Frame July 11, 1924.

An object of theinvention is to provide an antenna particularly adaptedto the transmission or reception of short wave lengths.

Another object of the invention is to provide an antenna particularlyadapted to the transmission or reception of short wave lengths which hasall the antenna structure supported at an appreciable height above theground. I

Still another object of the invention is to provide an antenna for shortwave lengths having a counterpoise supported at an appreciable distanceabove the ground.

' Still another object of the invention isto provide a short wave lengthantenna which will be directional in its effects and which will besupported at an appreciable distance above the ground. g

It is well known that a very good antenna adapted to the sending out ofwaves of mean and great length: can be built by means of a horizontalsheet ofwires suspended from towers of as great a height as possible andconstituting the aerial properly so called, a'

lead being convenientlybrought down to one pole of a high frequencysource mounted on the ground. The other pole of the sourceisin'communication with a second horizontal sheet of wires situated belowthe former, and

at a slight distance above the ground, this latter part of the systemforming what is known as the counterpoise or screen." As a general rule,the fundamental natural wave of this system as hereinbefore outlinedfalls below the wave length. of the transmission wave.

Now, for the sending of short waves a. similar arrangement may bepreserved, and the antenna thus built .may be Worked on a 40 higherharmonic. However, if the operation with the fundamental wave shall bepreserved, it is also desirable to preserve the high towers conformablywith the devices and means disclosed in the present invention. As amatter of fact, in accordance with cal culation and experience, the roleof the counterpoise or screen becomes of so much greater advantage inthe presence of short wave lengths, the greater the distance of the saidcounterpoise above the ground.

Theinvention is illustratedby wayof eX- ample in the accompanyingdrawing in which: a.

Fig. 1 shows anantenna conformingto the inventiomand," w I 2 shows adirectionala'ntennacon forming tothe invention; 1

Referring .to Fig. 1, the towers-1,1, supf 'p ort thQ'hOTlZOIllJfillayer or sheet-of wires 2, at. as great adistan 'ceaboveground'asfeaslble; below sald wlres'there is arranged at 3.acounterpoise,insulators 4:..b611lg111 areav than thearea covered by thesuperposed sheet of wires. .On the otherhand,the down lead 5 of:the saidsheet of wires canbe disserted; upon the various suspensionlcables.

be notedtha-t the screen 3may cover a-lariger f posed in various' ways;more" particularly speaking, 1t may comprise elther a single wire, orelse acertain number of parallel -wires. -Moreover, the part/of thedown-lead ,5which is locatedbeflow the 'counterpoise'fi can beconstituted in a different way from the, other part; -More particularlyspeaking, .togetherwith. the conductor 6 connecting the :counter'poise;with. the hf source,-fit could constitute areal doubleenergy-transmission line possessing convenient. characteristics,

Fig.

another solution comprising likewise the use 1 of towers 1 of relatively*greatheight. The

Q lilzewise shoivsway of example, s5

oscillator properly so called is here constituted by a wire (or systemof wires) 9 eXcited in. any desired manner by a'high frequency source(not shown) and with the endin view of realizing a directive action,there is arranged in well-known manner along a parabolic base a seriesof vertical wires 10 forming i a reflector. These wires constitute asmany oscillators excited inductively, and they are preferably tuned tothe local oscillator 9. The latter, as is well known also, could bedispensed with provided that the oscillators 10 are respectively fed bycurrents having relatively convenient phase relations, etc.

v Itgoes Without sayingthat a greatnumber jof modificationsnreco-nceivable. j For in stance, the two layers of Wire Q'andfi of Fig. 1v. ceuldbe disposed verticelly qr 'eleei'inclined "n'ot .en1yWithreference to the ground; but I, "also with-.referencerto one anotherso as to v1 realizedirectionel-efiectseither a hepizlon-fl v tailplaine-vonielse in the vertical planeyerel'se egain inbothFurthermore,,the aerial may ,7 V e a d 0 in all ca'ses be excited by ahglll ljQIliC necee I 1 stay, in well-knownmanne't. j

Finally, the Source of high frequency cur 7 rent may itself be mountedat a great height abovethe reimdiieninstence,upoe e nte c mediateplatform ofajtower. This arrange. v

mentmay be of; advantage in'the case'of a w Vtriodegenerator plant;thefeeding source for I v r j 'these triodes being then placed On the ram 7V "and'beingi connectedxwith the high'frec 'lency r apparatusthrough'convenient c'eblesz i' d Having'describedmyinventionjl claim: .7r y e 1. 'Anrantenna system "for the em'issionso'f 1 shgx t wzvvescomprising a Sheet-antennmup; portedyiont owers fixed- :to [the ground,atgca v relatively great; distance f above ground; and

cennterpoise; jsupportedsimilar; tof's said V V gantennafbfsaidantennalikewisesuppdrted g V "at aielativdygreat' distanceabove,ground,

. theldistancebetween said antenna andicounterpoise being-equal toorzleesrth'an the dis- Vta'nce between said countegpoise andgreund. EZIAn antenna system fbrthelemission oi V 7 v shdrt'waves comp-risingwsheebnn-tenna-sup .ported' gt a- ;re1 ati e1y -.greatdistanceab Ve J cg '1 3 ground;*01'1t0wers fixed to'the greund,iandcounterpoise;"insulated"from the grb-undfior' said antenna likewisesupported at a relative V I 1y great distancewabove .groundon towers 7"fixedvt'o thegroundfihe distance befiween sqic'l 4efan't-enfia andconnterpoise beingequal tonn e v. e lessit hainthe'dietancexbetween{Saidcounter;- v f poise and ground, aJ-lefadl-in wire {-frqm the V c 7antenna connected to one pole'ofa high f-fed -quencyeource, India secondlead-in w-ire from 4-5 the counterpoise connected to the'qthenpole ofjsa i'd s0i1rce5'b0th of said leed -inwires c611- stit'uting a doubleenergy-transmission line.-

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